Alzheimer's Disease (AD), the most common cause of dementia in the elderly, is estimated to affect over 4 million Americans, a number projected to grow in the next few decades. Research progress has led to improved diagnostic accuracy for AD, the development of symptomatic medications, and provision of social and community care networks. However, current treatment options provide only temporary stabilization at best, and the overall cost for care of patients with AD in the USA exceeds $100 billion per year. Further research is essential to make progress in the fight against AD. The UCSD Alzheimer's Disease Research Center (ADRC) has contributed to much research progress in the past 25 years. In order to facilitate and conduct research into the causes, treatment and prevention of AD, the overall Specific Aims of this renewal application for the Center are: 1) To support research efforts by maintaining resources that include cohorts of subjects with normal cognition, AD and other dementias; neuropathology tissue from well-characterized subjects; biological samples and DMA; and to maintain a comprehensive database. 2) To coordinate pilot and research projects related to Alzheimer's Disease, aging or neurodegeneration. 3) To foster professional education and training, as well as educational outreach efforts in the community. 4) To collaborate with other ADCs, with NACC, and with national research efforts related to AD and dementia. The Center will consist of an Administrative Core, a Clinical Core (with a Hispanic Minority Satellite), a Neuropathology Core, a Data and Biostatistics Core, an Education and Information Core. Three research Projects are proposed: 1) Structural MRI analyses to distinguish patients with AD, Dementia with Lewy Bodies (DLB) and Controls. 2) Axonal transport of a-synuclein and the pathogenesis of DLB. 3) Psychometric prediction of the rate of progression of AD and DLB. Three Pilot Project awards will be issued each year. The Center will follow 500 subjects, using annual standard evaluations that include the Uniform Data Set components and will contribute to national research efforts by contributing data to the National Alzheimer's Coordinating Center, and to the Alzheimer's Disease Neuroimaging Initiative (ADNI). ADRC subjects will be offered participation in clinical trials organized by the Alzheimer's Disease Cooperative Study (ADCS) and by pharmaceutical companies. The Center will continue to support innovative research, to train new investigators, and to improve public knowledge and awareness about aging and AD, as well as to provide innovative support efforts for patients and families affected by AD.